1. Field of the Invention
The present invention relates to a hermetic compressor for use in a cooling cycle system and, more particularly, to a quiet running compressor which has a simple cushion, or buffer, arrangement for absorbing very high pressure build-up in the discharge, or exhaust, system during the exhaust period of refrigerant.
2. Description for the Prior Art
According to the prior art, one type of a quiet running compressor is disclosed, for example, in U.S. Pat. No. 4,427,351 or British Pat. No. 1,140,452. In both of these patents, a space for cushioning the high pressure is provided on the exhaust side of the pump, thereby reducing the noise caused by the release of high pressure fluid through the discharge passage.
However, according to the prior art quiet running compressor as mentioned above, the space for cushioning the high pressure is located subsequent to a pressure applying space. Therefore, the top clearance of the compressor must be made large which deteriorates the compression efficiency.
Another type of quiet running compressor according to the prior art is disclosed, for example, in U.S. Pat. No. 3,857,652. According to this reference, the muffler for reducing the noise is located on the downstream side of the discharge valve. However, this arrangement has a problem in that extra space is required inside the compressor, resulting in a bulky compressor, and also, the noise reduction can not be done with a high degree of efficiency.
Yet another type of quiet running compressor according to the prior art is disclosed, for example, in Japanese Utility Model Laid-Open Publication (unexamined) No. 36505/1978. According to this reference, two discharge valves are provided, one over the other, for reducing the noise. However, the arrangement does not sufficiently suppress the vibration of discharge valves caused by the rapid change of amount of flow of refrigerant gas produced from the discharge port.